There are a variety of apparatus available for styling hair. One form of apparatus is known as a straightener which employs plates that are heatable. To style, hair is clamped between the plates and heated above a transition temperature where it becomes mouldable. Depending on the type, thickness, condition and quantity of hair, the transition temperature may be in the range of 160-200° C.
A hair styling appliance can be employed to straighten, curl and/or crimp hair.
A hair styling appliance for straightening hair is commonly referred to as a “straightening iron” or “hair straightener”. FIG. 1 depicts an example of a typical hair straightener 1. The hair straightener 1 includes first and second arms each comprising an arm member 4a, 4b and heatable plates 6a, 6b coupled to heaters (not shown) in thermal contact with the heatable plates. The heatable plates are substantially flat and are arranged on the inside surfaces of the arms in an opposing formation. During the straightening process, hair is clamped between the hot heatable plates and then pulled under tension through the plates so as to mould it into a straightened form. The hair straightener may also be used to curl hair by rotating the hair straightener 180° towards the head prior to pulling the hair through the hot heatable plates.
A hair styling appliance for crimping hair is commonly referred to as a “crimping iron”. FIG. 2 depicts an example of a typical crimping iron 10). The crimping iron includes first and second arms. Each arm comprises an arm member 14a, 14b and heatable plates 16a, 16b coupled to heaters (not shown) in thermal contact with the heatable plates. The heating plates have a saw tooth (corrugated, ribbed) surface and are arranged on the inside surfaces of the arms in an opposing formation. During the crimping process, the hair is clamped between the hot heatable plates until it is moulded into a crimped shape.
A hair styling appliance for curling hair (not shown) typically has a single arm bearing a cylindrical heater, not necessarily of circular cross-section, around which the hair is wrapped.
Hair styling appliances typically have a ceramic heater, which aids optimisation of the thermal control loop, thus allowing the plates in contact with hair to remain near transition temperature during styling and thermal load application. This leads to longevity of style.
Conventional ceramic heaters typically comprise a layered structure having an electrical heater electrode sandwiched between two layers of ceramic/embedded within the ceramic plate. A heatable plate is then thermally coupled to the heater, on one side of the heater/ceramic sandwich, which provides a contact surface for styling hair.
The temperature range required, user expectations with regard to the time to heat-up, thermal control, and other factors combine to drive existing hair styling appliances to employ mains power for the heater(s).
The inventors have, however, recognised that a paradigm shift is possible.